Peacock Bass - Pioneer R - Mackay

[Ducksta]

These guys would need a heater anywhere the water temp drops below about 20 over winter.
Growth rates in a good aquarium system will be up over an inch a month.
The species we have in the hobby here are Cichla monoculus (or likely a hybrid that is very mono heavy from before all the species were properly described.)
I'd class them as highly predatory, but not very aggressive at all - except when defending a nest or fry ball.
To explain, yes they will chase down anything they want to eat - but otherwise they are quite mellow.
They are not difficult to keep with other (appropriate sized) fish at all which is generally a marker for aggression. They don't beat up and kill stuff just to do that.
In fact, my saratoga killed my last 6 peacock bass, because my saratoga is a total arsehole.

These are one of the smaller species of peacock.
Depending who you ask these may or may not be the same species as were released in Florida.
IGFA recognises peacocks from Florida as monoculus, but they started out by breeding fish collected from several countries and many suspect they have their own hybrid strain there too.

Regarding the chances of establishing. In Florida they released over 20,000 "butterfly peacocks" to get them to establish.
They also released 110 larger/adult 3 bar peacocks (ie. the big ones people go to the Amazon for) and have reported no captures of any juvenile fish ever, and none of the adults in decades which suggests that was not enough to start a population (of that species).
Interestingly, their release in Florida is considered a success because the biomass of other introduced (pest) species was reduced while populations of some natives actually increased.
Obviously Mackay isn't Miami, so fingers crossed whatever is in there gets knocked on the head before they get any chance to cause a problem.

If it really was 4 proven breeding pairs then it shouldn't be hard to find out who it was, as there wouldn't be many people who have that kind of setup.

Are there any rumours about when they might have been released? The pic circulating now doesn't really look like a happy fish. Physically it's in good nick - with fins etc all in tact, but the colour is washed out like it's not really loving life.